Comment 17 for bug 834403

The backtrace indicates that this is happening inside canbera:

...
#4 gdk_x_error (xdisplay=<optimized out>, error=0x7fff50bf0dc0) at /build/buildd/gtk+3.0-3.1.12/./gdk/x11/gdkmain-#5 0x00007fd41d5a301f in _XError (dpy=0x2425370, rep=<optimized out>) at ../../src/XlibInt.c:1583
#6 0x00007fd41d59fdd1 in handle_error (dpy=0x2425370, err=0x7fd408707980, in_XReply=<optimized out>) at ../../src#7 0x00007fd41d5a0d27 in _XReply (dpy=0x2425370, rep=0x7fff50bf0f60, extra=0, discard=0) at ../../src/xcb_io.c:698
#8 0x00007fd41d5852fb in XGetWindowProperty (dpy=0x2425370, w=0, property=348, offset=0, length=2, delete=#9 0x00007fd41938269e in window_is_xembed (w=<optimized out>, d=<optimized out>) at canberra-gtk-module.c:373
#10 dispatch_sound_event (d=0x32f6a30) at canberra-gtk-module.c:454
...

I suspect there is a missing gdk_error_trap_push/gdk_error_trap_pop_ignored() here.I attach a small test program that demos the crash.